I have this Desjardini tang for over 2 years now. The fish eat well everyday. They day before yesterday, he ate really well, chasing food and such. I came home last night to find him stuck to the powerhead. I immediately turned everything off and got him off. He began to swim sideway for a while, and began to stuck to the PH again. I moved him to the sump. I didn't see any white spot on him, no other sign of disease. He looks much thinner than the previous day, also noticed that he developed a lateral line erosion which wasn't there the day before. Other his fins being torn, there are no damage to the body. As of this morning, he is up right and moving around in the sump.